It is known to manufacturer flat particle board from comminuted wood by mixing the wood particles with a suitable binder, such as a synthetic thermosetting resin, forming the mixture into a mat, and then compressing the mat between heated platens to set the binder and bond the wood particles together in a densified form. This type process is exemplified in U.S. Pat. Nos. 3,164,511 (Elmendorf) 3,391,233 (Polovtseff) and 3,940,230 (Potter).
In this type process, the wood particles are deposited so they are either randomly oriented relative to each other or oriented to cross each other. For example, the Elmendorf U.S. Pat. No. 3,164,511 discloses orienting the wood particles or strands so that substantially all cross at least one other strand at an average acute angle of less than about 40 degrees. Products having strength properties which are acceptable for typical applications of flat particle board can be produced from processes wherein the wood particles are randomly oriented or oriented in the manner disclosed in the Elmendorf patent. However, structural members of 1-inch thickness or more produced by such processes generally have strength properties, particularly bending strengths along the longitudinal axis, which are somewhat inferior to solid wood.